Specific growth rate (SGR) achieved in pikeperch fingerlings in all experimental groups of pikeperch fingerling: pikeperch with trainer fish and direct application of pelleted feed – A (PF); pikeperch with trainer fish and gradual addition of pelleted feed to natural food – B (PF + NF); pikeperch without trainer fish and direct application of pelleted feed – C (PF); pikeperch without trainer fish and gradual addition of pelleted feed to natural feed – D (PF + NF). Data are presented as mean, standard error of mean (SEM), and standard deviation (STD). Values with different superscripts differ significantly (α = 0.05).